The present invention relates to covalently binding organic materials to the surfaces of polymer substrates by functionalizing the surfaces with linker moieties containing transition metal complexes. In particular, the present invention relates to modifying polymer surfaces with organometallic compounds that have functional groups that react with functional groups of the polymer surface. The modified polymer surface can be further reacted with a compound, polymer or oligomer that contains functional groups that are reactive with functional groups of the organometallic compound that remain after reaction with the polymer surface. The present invention further relates to functionalizing polymer surfaces to support cell growth and the attachment of biologically active molecules and other compounds of interest.
Bioactive polymeric scaffolds are of increasing importance for use in tissue regeneration in a variety of clinical applications, and a scaffold that supports cell growth is a critical first step in such regeneration. Surface wetting properties of many polymers used as bioscaffolds are not conducive to biointegration, but incorporation of surface functional groups can effect substantial changes in a polymer's wettability while generating reactive sites suitable for attachment of peptides and other biomolecules.
Adjustment of the surface properties of polymers such as those from which preformed polymeric therapeutic devices are formed, has proven problematic because those polymers most often used as biomaterials are resistant to specific surface treatments. To circumvent this problem, polymer scaffold materials have been prepared by blending, copolymerization, or physical treatment, but these methods can result in alteration of the bulk properties of the polymer. Furthermore, these methods or attempts to surface modify pre-cast polymers using standard methods of organic synthesis, result only in low surface coverage by peptides that do not approach those that can be achieved on metallic substrates.
Surface modification has also proven problematic in other areas of polymer and polymer surface customization. There is a need to modify polymer surfaces so as to change the surface characteristics of the polymer surface without changing the bulk properties of the polymer. More particularly, there remains a need for polymer surfaces that support cell growth as well as the attachment of biologically active molecules and other compounds of interest.